Corrector system for synchronous telegraph apparatus



May 3, 1932- H. H. HAGLUND 1,856,331

CORRECTOR SYSTEM FOR SYNCHRONOUS TELEGRAPH APPARATUS Filed Aug. 28, 19292 Shee'tS-Sheekl 2 NEO/V LAMP E CORRECTOR P/Ch UP RINGS ff W 9 W w 12EN" IHI IHI IHI IHI IIII 1H! lll IHVI [Tl Y Fl l V VT COHREC TOI? F//VGS nnentor HHHagZund Patented May 3, I 1932 UNITED STATES .PATENT OFFICEHAKON H. HAGLUND, OF FLUSHING, NEW YORK,. ASSIGNOR TO THE WESTERN UNIONTELEGRAPH COMPANY, F NEW YORK, N. Y., A CORPORATION 0F NEW YORK CORECTORSYSTEM FOR SYNCHRONOUS TELEGRAPH APPARATUS Application filed August 28,1929.

This invention relates to a system for maintaining synchronism between arotary distributor at a receiving station and incoming signals on atelegraph line.

An object of the invention is to devise a corrector system employing asteep-wave front transformer or a transformer producing sharp voltagepeaks in the secondary when telegraphic currents are supplied to theprimary. Y

A further object of the invention is to devise a corrector system whichwill maintain synchronism with a high degree of accuracy.

A further object of the invention is to devise a corrector circuit inwhich the corrector relay operates at a speed lower than the linesignals.

My invention is illustrated in the accompanying drawings in which:

Figure 1 shows one form of my invention employing an electromagneticpick-up relay;

Figure 2 is another form of my invention employing a gaseous type ofpick-up relay commonly known as a thyratron; and

Figures 3 and 4 "are curves illustrating the 1 operation of thetransformer employed in my system.

Referring to Figure 1, L indicates a telegraph line supplyingtelegraphic signals to the input of amplifier A, the output circuit ofwhich is connected to the primary of a special transformer T. Oneterminal of the secondary winding of transformer T is connected to thesolid ring R1 of the corrector rings through the operating winding (O)of` pick-up relay PR. The other terminal of the secondary is connectedto alternate segments of segmented ring R2 of the corrector rings. Bindicates the rotating brush associating the segmented and solid rings.Thepick-up relay PR is provided with a locking winding P, one terminalof which is connected to neutral battery and the other terminal isconnected to one terminal of the locking resistance R and to the contacton corrector magnet CM. The tongue C1 of pi ck-up relay PR is connectedto the remaining terminal of locking resistance R and to one terminal ofthe corrector magnet CM, the remaining terminal of the correcting magnetbeing con- Serial No. 389,032.

nected to negative battery. The right-hand Contact of pick-up relay PRis connected to positive battery. The tongue C2 of corrector magnet CMis connected to negative battery, and also operates a pawl D which isassociated with a ratchet wheel RV mounted upon the shaft of the rotarybrush B. Armature C2 of the corrector magnet is biased to the right handposition by a spring S.

The special transformer T is a steep-wave front transformer such asdescribed in General Electric Review for March 28, 1928,

pages 136 to 138. The special transformer has a magnetic circuit with areduced cross section' at one point to increase the rapidity with whichthe core becomes saturated. The saturation effect of the core producesvoltage impulses like that shown in Fig. 4f for a positive and anegative signal impulse supin the output circuit of amplifier A ischanging from spacing to marking, a flux will be set up in transformer Twhich will produce a voltage impulse in the secondary. If thedistributor brushes B are in phase with the incoming signal, they willat this moment be upon a dead correcting segment, but since thesecondary of the transformer is open, no correct-ion will take place.If, however, the brushes are out of phase with the incoming signal, thesecondary circuit would be closed by the brush between the solid ring R1and alive corrector segment. The current iowing in the secondary willoperate the pick-up lrelay PR to its marking position thereby will lockthe pick-up relay with its tongue on its marking contact. The secondcircuit may be traced from positive battery on the marking contactthrough the tongue of the pick-up relay, and through the correctormagnetWinding to negative battery. This circuit operates the corrector magnetto establish another circuit from neutral battery through biasing coil Pof the pick-up relay, through the contact of the corrector'magnet, andthrough the corrector magnet armature to negative battery. Since thecurrent established by the circuit just traced flows in a directionopposite to that previously established in the locking coil P, thiscurrent will reverse the pick-up relay and restore the tongue to itsspacing contact ready for operation again in response to the incomingsignals. The closing of the corrector magnet contacts also permits acurrent to liow from positive battery through the tongue pick-up relay,through locking resistance R through the tongue on the corrector magnetto negative battery. This current is only incidental and has no harmfuleffect upon the operation of the circuit, provided the resistances oftbe various circuits are properly proportioned. When the correctingmagnet operates, pawl D engages ratchet wheel RW and steps it back onetooth to place the brushes B in proper phase with the incoming signals,as is well understood.

When the signal current reversesk from marking to spacing, the voltageproduced `in Ithe secondary of the transformer would tend to throw thepick-up relay to its spacing contact. The locking circuit, however,prevents this happening while a correction is taking place, and when thecorrection is completed, the pick-up relay is returned to its spacingcontact automatically so that the tendency to throw the relay to itsspacing contact has no effect. Accordingly, correctiont-akes place onlyon changes from spacing to marking signals, but by reversing one of thetransformer windings it can, of course, be made to correct on changesfrom marking to spacing.

In Figure 2 I have replaced the magnetic pick-up relay by a gaseousrelay commonly known as a thyratron, which comprises a gas-filledthermionic tube of such construction that when the anodeis connected topositive battery and a certaln potential is applied to the grid, thetube will start and current will flow from the anode to the cathode. Assoon as the plate current begins to flow the grid is instantlysurrounded by a sheath of positive ions and has no further efect. Thissheath, usually only a fraction of a millimeter thick, contains thewhole voltage drop between the grid and the space surrounding it.Changing the grid voltage merely changes the thickness of the sheath andhas no effect on the potential of the rest of the likened to a trigger.The amount of power required to start the tube is exceedingly small. Athermionic tube having the characteristics described is disclosed inpatent to Irving Langmuir No. 1,289,823. The name Thyratron has beenapplied to tubes of this type in an article entitled Gas-filled thermieomc tubes by A. W. Hull, published in the Journal of the AmericanInstitute of Electrical Engineers, November 1928, page 802, in whichother forms are described.

The secondary circuit of transformer T includes a resistance R3 and aneon lamp NL connected in series. @ne terminal of resistance R3 isconnected to the cathode of the thyratron relay TR and the otherterminal is connected to the solid ring R4 of the corrector pick-uprings. The segmented ring R5 of the corrector pick-up rings is connectedto the grid element G of the thyratron tube. The rotating brush Bl isassociated with the solid and segmented rings of the corrector pick-uprings. The plate circuit of the thyratron tube includes a battery 2,segmented ring RG, rotating brush B2, solid ring R7 and the correctingmagnet CM. The plate circuit may also be completed through battery 2 andcorrector magnet CM by way of a commutator 3 and brush 4 associated withlratchet wheel RW. Ratchet wheel RW has a lclutch connection 5 with theshaft carrying rotating brushes B1 and B2, the same as in Fig. l.

Operation of the arrangement shown in Figure 2 is as follows: If therotary distributors at the transmitting and receiving stations arerunning in proper phase relation, the corrector brush B1 will be out ofcontact with the segments on ring R5 when a signal impulse is receivedover the line, and the thyratron relay TR will not be operated. If thedistributors are not in proper phase relation when a signal impulse isreceived, contact will be established between a segment on ring R4 andring R5 by brush B1, thereby impressv ing upon th grid G the potentialdrop across resistance R3, which will start plate current flowing in theplate circuit and energize the corrector magnet CM. Upon operation ofthe corrector magnet, awl D engages the tooth on ratchet wheel `W, andas soon as the ratchet wheel begins to move, contact is establishedthrough commutator 3 and brush 4 so that current from battery 2continues to flow through corrector magnet CM to thyratron TR regardlessof the position of brush B2, thereby insuring the completion of thestroke of the corrector. The current through corrector magnet MC isautomatically out olf at commutator 3 upon the completion of the strokeof armature C2, and the armature,

lWith pawl D, is returned to its original position ready for operationagain by incoming signals.

Due to the peculiar conduction characteristic of the neon lamp NL in thesecondary circuit of transformer T, the action of the lamp may belikened unto that of a switch element for abruptly opening and closingthe circuit, thereby accentuating the peak of the secondary current.

It may be found desirable to connect a battery 6 and a resistance 7between the cathode and the grid of the tube to maintain the gridsuiciently negative to prevent its starting except when a pulse isreceived through the pick-up segments.

tributor, corrector means associated with said distributor, a pick uprelay for controlling said corrector means, and a saturated transformerconnecting said pick-up relay and said distributor to said line.

2. A corrector system ycomprising thevcombination of a telegraph line, arotary distributor, a pick-up relay, and a saturated transformer, saidtransformer being connected to said line and having said rotarydistributor and said pick-up relay connected in series in the secondarycircuit thereof, and a corrector mechanism controlled by said pick-uprelay. l

In a corrector system, the combination of a pick-up relay having anoperating Winding and a biasing Winding,v a correcting device includinga corrector magnet. a circuitv controlled by said pick-up relay forenergizing said corrector magnet, and a second circuit controlled bysaid pick-up relay including said biasing coil for biasing said relay toits operated position.

4. In a corrector system, the combination of a pick-up relay having anoperating` winding and a biasing Winding, a correcting device includinga corrector magnet, a circuit controlled by said pick-up relay forenergizing said corrector magnet, a second circuit controlled by saidpick-up relay including said biasing coil for biasing said relay to itsoperated position, and circuit connections-` controlled byv operation ofsaid corrector means for deenergizing said biasing coil upon completionof the corrector operation.

5. A corrector system comprising the com-r bination of a telegraph line,a rotary distributor, corrector means associated with said '65.distributdr, a pick-up relay for controlling said corrector means, asaturated transformer for associatingsaid pick-up relay' and saiddistributor with said line for initiating operation of said correctormeans when said distributor is out of synchronism with signalstransmitted over said line, and means for maintaining said correctormeans energized until the correcting operation is completed. G. Acorrector system comprising the combination of a telegraph line, arotary distributor, a pick-up relay comprising a thyratron tube,corrector means operated by said pick-up relay, and a saturatedtransformer for connecting said rotary distributor to said line throughthe input circuit of said pickaip relay.'

7. A corrector system comprising the combination of a telegraph line, asaturated transformer connected to said line, a pickup relay comprisingathyratron tube, a rotary distributor including two sets of solid andsegmented rings With cooperating brushes, the secondary of saidtransformer being connected to the input of said thyratron tube throughone set of said rings, corrector means associated vvith said distributorincluding a corrector magnet, said magnet being included in the platecircuit of said thyratron tube in series with the other set of rings,and means embodied in said corrector means for maintaining saidcorrector magnet energized until the corrector operation is completed.

8. A corrector system comprising the combination of a telegraph line, arotary distributor, corrector means associated with said distributor, apick-up relay for controlling said corrector means, a saturatedtransformer connected to said line, a resistance and a neon lampconnected in series in the secondary circuit of said transformer, andcircuit connections for-controlling said pick-up relay by the drop inpotential across said resistance.

In testimony whereof I affix my signature.

HAKON H. HAGLUND.

f "DISCLAIMER 1,856,331.Ha kon H. Haglum, F1ushng,N. Y. GORRECTQRSYSTMFOR SYNcHB-- NOUS -TELEGRAPH'APPARATUeL Patent dated May 3, 1932.Diasclaime` filed N ovembelr` 2, 1933', by the patentee, assignee, TheWestern Union Telegraph Company, assent-ing. Hereby entersaJ disclaimerto that, part of the subject-matter of Patent No. 1,856,331, dened inclaims 1, 2, and 5 thereof.

[Qjcial Gazette December 5, 1.933.]

